two percenter

noun2

1. •
   (US, informal) A student of Texas A&M University who only attends classes and does not participate in student activities or traditions.

   • "Those are the 'two percenters,' " Becky said of the students who ran on the field, "the two percent of Aggie students who don't have the spirit." — 1992
2. •
   A joke or reference that is so obscure that only a small minority of the audience will recognize and understand it.